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The longer battery life in laptops, which have become ever cheaper, coupled with greater coverage of the fastest flavors of 3G, mean that students can actually get real work done that requires an Internet connection. The bus driver reports less rowdiness, and teachers are seeing more homework.

For business travelers, ubiquitous access in planes, trains, buses, and ferries might still mean an extension of the work day instead of a displacement of formerly useless time into productive activities. But for students on buses, the time can be lost--and then displaced into evening hours, reducing their time for unstructured activities.

Lest you think this is a rural issue, my wife recently calculated that when our 5 year old heads to middle school in several years, the busing system would probably require he spend 80 minutes on a bus to get to a school about a 10-minute drive away.

One school he speaks to has 80 to 90 percent of its Ethernet switch capacity unused. The CalState system performed careful analysis of current use and opted to cut 2,500 switches, which will save $30m in hardware-related spending, exclusive of HVAC/electricity savings.

At colleges, this is a simpler matter, because campuses can simply eliminate new spending for Ethernet in dorms and elsewhere and pull switch plates and switches, or reduce the number of jacks by a large number without impairing functions. While some students might have desktop computers, surveys keep finding that most arrive at campus with laptops or purchase them on arrival. Businesses may still need to have Ethernet active because of their heavier desktop use.

For instance, in a 2008 survey of incoming students at the University of Virginia, with 95 percent of students surveyed, a single person in the 3,071 asked did not own a computer. That number was as high as 26 percent (634 of 2,437) in 1997, but has dropped to a negligible amount since 2003 (30, 10, 18, 4, and 4 in successive years had no computer).

Now out of those 3,070 computer owners in 2008, only 36 had desktops. That's a lot of spending on Ethernet for 1 percent of students. And those desktop systems might have had Wi-Fi built in if they were Macs (Mac Pros are the only model that requires an add-on build-to-order Wi-Fi adapter) and most student/entry-level oriented Wintel systems.

802.11n found its way into colleges quite early, but enterprises now have a wide range of affordable options from major and minor vendors alike that are proving more cost effective than 802.11g or a/g was because of the greater capacity and range of 802.11n. Everything I hear from companies and read in reports shows that dual-band 802.11n overcomes almost ally of the gating factors that made 802.11g useful but not strictly a wired replacement for clients.

Most clients don't need anything like the 100 to 150 Mbps throughput that 802.11n can offer in ideal cases. Rather, each client may need from 1 to 10 Mbps in a more or less reliable and guaranteed fashion, and with a multi-channel switched WLAN, enterprises can easily deliver that.

College campuses have lower requirements, seemingly, with Cox noting that 1 Mbps is a reasonable threshold for common activities. In those cases, you need networks that can support massive concurrent users in relatively small areas, like classrooms or quadrangles, a very different requirement from the business network.

No one's suggesting Ethernet will be pulled out. It's still the only way to run critical services, and you need quite a lot of it to backhaul all the WLAN systems that are being put in. But there's a growing divide between client Ethernet and server/backhaul Ethernet that can let companies and colleges trim their IT budgets without reducing utility for their users.

April 14, 2008

Driving, biking, and walking to gain a sense of Wi-Fi geographies: Paul Torrens wore out the patience of his friends and family, but gathered 500,000 Wi-F samples across a 12 sq km area of Salt Lake City, Utah, for his paper "Wi-Fi Geographies," published in the 1 March 2008 issue of Annals of the Association of American Geographers. (The paper can be downloaded for a fee, but may be available through local public or academic libraries, too.)

In an interview recently, Dr. Torrens, an assistant professor at Arizona State University in the School of Geographical Sciences, said that he used his extended family to help him gather the data necessary to draw real conclusions. "Any time they were going anywhere, I got them to stick the rig to their car."

Dr. Torrens said that he decided to attack Wi-Fi because it was hard in the geographic field to find a subject area that hadn't been throughly explored, and that his interest in patterns and process over a landscape led him to Wi-Fi. His exploration looked at Wi-Fi as a topology overlaying population, demographics, and architecture.

In examining the literature to see if scholarly research had been carried out, he found a lot of wardriving details, but not a lot of accuracy or analysis. The maps of Wi-Fi coverage that are out there "rely on people going out and wardriving and submitting the data to some sort of online repository," Dr. Torrens said. While they may use GPS for timestamping and logging samples, "Unless you really know what you're doing with it, it provides very weak spatial accuracies [and] positional accuracies."

Dr. Torrens said, "I was able to come up with a much better accuracy." Some of his work is patented, and he said that while the university assembled the materials to file against his work, he remained a bit quiet about it. (As with most universities these days, ASU actively seeks to patent and license research as one means of funding the university's future.)

The data that he found in wardriving databases didn't account for quality, very few samples had timestamps, and where he found huge clusters, it didn't account for the timeframe, and thus was hard to tell whether the clusters existed at the same point in time. Dr. Torrens was collecting his data in 2005; wardriving databases may have improved in that time.

Dr. Torrens said that using techniques from the field, he could associate samples together, determining whether a cluster was legitimately such, or an abberration in the data--"whether a cluster is a cluster," in other words.

The research revealed some expected results, such as an extremely high number of access points in the most densely inhabited parts of town, but Dr. Torrens said he didn't expect to find that less-populated parts of town would also have a nearly ubiquitous spread of nodes. One area "that's relatively underpopulated is a whole warehouse district," he said, and they had lots of access points.

In the least-covered areas of the city, about seven access points were "visible"; in some places, that number was as high as 43 access points.

Also interesting to note was that security was most frequently enabled on Wi-Fi nodes in the parts of town dominated by students, who obviously had the technical jobs and understanding to prevent others from gaining access to their networks.

Dr. Torrens may carry out more Wi-Fi related geographic research, but that partly depends on having the resources or capability to gather information on a large scale. He'd love to gather live data that would allow him to show patterns as they change across the time of day or over a period of time.

"What I would like to do is to look at a temporal snapshot of the city, to look at how the Wi-Fi cloud is changing over time, over the course of a week," he said. "What is the temporal topography, the space-time topography of a city."

"To collect this kind of data set in real time would require a couple hundred thousand people with iPhones, citizen volunteers," he noted, but that might be possible with the capabilities of an iPhone software toolkit, promised by Apple in June, or through data sets gathered by firms like Skyhook Wireless.

May 24, 2007

Interesting sidenote to EarthLink getting a passing grade on its test network in Philadelphia: Drexel University has struck a deal announced today that will allow its tens of thousands of users access to EarthLink's network in Philadelphia and other EarthLink networks in the U.S. Terms weren't disclosed, if any. It's a one-year pilot project. Drexel has 28,000 registered network devices and nearly 20,000 students. Greater Philadelphia sports over 80 institutions of higher education that enroll 300,000 students each year. Drexel will continue to operate its own Dragonfly network on its campuses; this is an interesting extension, and a great way to win customers who pay as each class graduates.

October 10, 2006

The Campus Computing Project says 51.2 percent of college classrooms have wireless network access:That compares to 42.7 in 2005 and 31.1 percent in 2004, they state in a new survey. 68.8 percent of surveyed campuses have a strategic plan for deploying wireless, too. The survey found that community colleges have substantially fewer wireless classrooms than four-year colleges and universities. Network and data security was selected by 30 percent of respondents as their single most important IT issue, which goes hand in hand with wireless networks.

October 9, 2006

Aruba thinks it may be part of the creation of the world's largest wireless local area network (WLAN): I'm not quite sure if they're right, but they make a good case. The network will require between 3,000 and 10,000 APs. On the short end of that range, there are plenty of campus-wide (academic and business) networks in that scale. But on the higher end, I'm unaware of anything that large. Even city-wide networks like Philadelphia should employ only the mid-thousands of nodes, although they're not providing the same kind of high-availabily, in-building overage that Ohio State will have.

The stats: 50,000 students, 27,000 faculty/staff, 25 million square feet across 400 buildings, and 1,700 acres. In three weeks, they've lit up 1,700 APs in 28 buildings. I assumed that was the time to get the network running, not both physically stringing APs and logically activating the network--but I'm apparently wrong. Read the comment below. [link via Engadget]

August 29, 2006

Canadian university mocks president, my alma mater: The Yale, Shmale campaign by Lakehead University does little to restore the luster to an institution, the president of which has banned a campus-wide Wi-Fi network due to unsupported, bad science that he nonetheless believes is prudent to work from. (Despite no epidemiological effects from tens of millions of people living and working in constant proximity to Wi-Fi transmitters. Perhaps we'll all drop dead en masse.)

The Yale, Shmale campaign is also offensive to Yinglish speakers, that blend of Yiddish and English, for appropriating the sing-songy rhyme used to indicate a dismissive attitude. Correct use: A member of the Whiffenpoofs described missing some midterms in order for the long-running campus singing group to perform the national anthem at a World Series game thusly--"Midterms, shmidterms! This is the World Series!"

August 8, 2006

It's not citywide yet, but it's a great effort for an after-school project: The Rochester After School Academy (RASA) is building a network with Wi-Fi nodes attached to 17 utility poles; the network could expand to 35 in this early phase. The student-staffed Rochester Digital Ripple will operate the network. The city of Rochester helped RASA negotiate access to utility poles, and will donate 35 computers for use at a community center.

The negotiations for these poles took--a year! Can I keep reiterating that the hand that rocks the utility pole rocks the world? Yikes. The efforts in this pilot project are part of the groundwork for plans for a citywide network. [link via Mike Thomas]

March 2, 2006

Scottsdale, Ariz., students who use spitballs on buses may be found out faster: Video equipment is installed on nearly all of the Scottsdale Unified School District's 85 buses, but transferring it in a timely and reliable manner was a problem. The new system uses digital video and Wi-Fi to store more information on the bus and transfer it when the vehicle returns to the bus barn. The video system is used mostly to meet the district's impression of federal requirements for tracking children on and off the bus.

The system can be equipped with cell data modems for remote viewing, but the district has no plans to carry that out. In the realm of accountability, it should be noted that the VCR system in place cost $1,200 per bus and the system that replaces it will be $1,400 per bus. How long were the VCR systems in use? Not noted.

March 1, 2006

The State of Victoria, Australia's Department of Education has rolled out 10,000 access points across 1,700 locations: Their first problem was convincing Cisco to disable the reset button on their routers. They did not want technicians to hit a button that would reset APs to a default state that lacked the security and other options that were considered baseline. They also found a weakness in Cisco's central management solution for WLANs in both cost and functionality. The technology security head for the department said that Cisco's devices couldn't traverse NATs (network address translation gateways) and would have cost $30,000. They built their own software in two hours.

The network uses generic AMD-based Linux systems to handle proxying and authentication in each of 1,700 locations. Interestingly, the security head said that Microsoft and Intel didn't find the rollout "interesting"--certainly because of the AMD and Linux components involved. The department is keeping its integration of open-source and free software components private at the moment, but said they are obeying licensing terms by contributing elements back to each project.

The report in the Lehigh University student newspaper recounts that the Wi-Fire was a student project that won a $2,500 prize at an entrepreneurial challenge. It's a neat idea, and the students behind it have founded hField Technologies. It's patent pending, and one hopes FCC license pending, too. Don't forget that detail, kids!

July 11, 2005

Vail, Arizona, high school ditches books, wires: The high school of 350 students will use laptops and electronic texts. The methodology of whether this works is based on the superintendent looking around at other schools, but apparently not viewing results like attendance, test results, and softer measures. Further, the article doesn't touch on the problem with electronic texts, that they're highly controlled for distribution and licensing and often have limited periods of use, such as a year or a school year. Conventional textbooks can last several years, be handed around, and even used by (gasp) more than one person at a time.

Until such a point that electronic textbooks have the same flexibility and usefulness--not just up-to-date-ness, when that's even happening--as print textbooks, the value of this switch is not documented, not supported by research, and not wise.

SyncScan relies on a feature in Atheros's chipsets that's available from the open-source madwifi drivers; it's the same sort of feature (if not the identical one) that allows Atheros's WLAN switch partners to offer RF monitoring on the same APs that are also handling client data interchange.

Two problems with SyncScan's approach: first, it requires firmware to be installed on the access point, which is fine for experimentation and open-source projects, but otherwise needs signoff from major firmware developers and their manufacturing partners; second, it's got that patent-pending label attached, which always has the caveat of causing resistance until fees are revealed.

SyncScan puts all APs within listening range of each other into a synchronized beaconing mode so that the "I'm alive" signals happen at fixed intervals. This allows adapters to only listen at discrete periods and to get a clear idea of precisely what's happening in the local RF space. But this coordination adds overhead and there has to be a cost to synchronization and the inevitable resynchronization.

One of the IEEE 802.11 groups, 802.11f, was dedicated to fast reassociation through preauthentication--tokens exchanged among APs at Layer 3--but that doesn't help with fast reassociation on an RF level, or Layer 1.

Dartmouth chose 802.11a not just because it lacks interference from lots of non-WLAN devices, but because they are using 802.11b-based VoIP phones, which means that these phones can steal quite a lot of time slots at each access points just by being in use if they had gone with 802.11g for video. Instead, video will stream at 802.11a, while voice and data can remain on 802.11b and 802.11g. (A commenter below notes that the article incorrectly states that the entire network drops to 11 Mbps when an 802.11b device associates: in fact, the 802.11b device just takes up more "space" on the network reducing the ability of 802.11g devices to broadcast by reducing the amount of open signal time.)

The network will quadruple access point raw numbers to get the density right to support Wi-Fi. They're switching from Cisco APs to an Aruba WLAN switch-based architecture to provide better signal and data flow management.

Dartmouth is also aggressively pushing VoIP: 4,000 of 7,000 phone lines on campus are VoIP, but the article notes just a few hundred use Wi-Fi. That's set to change, too, and they may adopt Vocera communicators based on the a reference in the article.

February 5, 2005

WiFiMaps.com releases massively large, detailed wardriving maps of Seattle: In conjunction with a University of Washington course. I can't describe it better than Drew:
Dr. Philip Howard from the communications department has been teaching his students about technology, ideas, people, and how culture is affected by these new concepts. Their project allows them to gain some practical experience while exploring Wi-Fi as it pertains to them and the people around them. Involving 100 students, this project is one of the largest collective efforts to map Seattle's wireless landscape.

WiFiMaps.com is a website which provides interactive maps of Wi-Fi installations, as seen by wardrivers. This collaboration served to create critical mass for the website to provide printable maps, in addition to on-screen maps that exist. Also, this paves the way for other universities and groups interested in orgznizing detailed scans of their city to have a way to actually accomplish this, and have visual results.

The files are BitTorrented because of their enormous size (over 100 and 300 MB). [link via Slashdot]

January 6, 2005

Colleges are the bleeding edge of WLAN technology: I wrote this piece for Mobile Pipeline (my first for them) which started out as a more general best practices article for giant WLANs, and morphed into an article about college WLANs. Why? As I explain in the story, giant WLAN enterprises don't want to talk on or off the record about what they're doing. Academic institutions are happy to oblige.

Schools also have the disadvantage of having to support many, many generations of equipment and operating systems. You can't tell a professor to take a flying leap, and some schools may still have five-year-old laptops and desktops that still have to be integrated.

It's clear that 802.1X is the next big trend for both schools and enterprises. It solves many problems while adding tremendous policy flexibility. Using 802.1X and L2TP means that you can have smaller VLANs that are segregated by policy, group, or even randomly to balance users among VLANs.

July 28, 2004

AUT will rely on Reach Wireless to install a campus-wide, commercial hotzone: In the U.S., we're used to universities and other educational institutions installing Wi-Fi as part of their basic infrastructure, including the cost of operation out of their physical plant or IT budget, alum fund, students fees (partly hidden), or other endowments. Auckland, New Zealand's technology institute has turned to commercial operator Reach Wireless, which employs RoamAD's quasi-mesh/cell Wi-Fi architecture, to deploy a hotzone across campus and handle the finances.

AUT will own the infrastructure and carry the hotzone's traffic over its own Internet feed. But Reach Wireless will operate the service, collect fees, and provided customer and billing support. Students and faculty will be charged NZ$16.95 (US$10.50) per month. Existing Reach customers and the general public will also be able to use the campus network. Current subscribers won't pay extra for access; vice-versa, AUT affiliated subscribers will have Reach within reach at a small additional cost off campus.

Here's the kicker from a press release: The network was designed in one day and deployed in less than a week.